Pushpins on foamboard. Trace your design first, buy twice as many pins as you think you'll need. If framing, cut foam board to frame first. - Cute way to use the push pins I bought for my DIY headboard and didn't end up using.
"Two-level library of a Mercer Island home designed by Kelly Wearstler." A small upstairs bedroom was sacrificed to make this, and the brass spiral staircase was custom-made. Probably any book-lover would love this.